The present disclosure relates to an electrophotographic image forming apparatus and a light guide member used in the electrophotographic image forming apparatus.
In an electrophotographic image forming apparatus, a photosensitive drum is uniformly charged by a charging roller. Next, laser light is applied to a surface of the charged photosensitive drum, and thus an electrostatic latent image is formed on the surface of the photosensitive drum. Then, the electrostatic latent image on the photosensitive drum is developed by using toner. Then, after the toner image on the photosensitive drum is transferred onto a transfer target member such as a sheet or an intermediate transfer belt, the photosensitive drum is discharged by discharging light emitted from a discharging portion, and the surface of the photosensitive drum is cleaned by a cleaning portion.
In some cases, a discharging portion, which applies discharging light to the photosensitive drum before transfer of the toner image on the photosensitive drum onto the transfer target member, is provided. Further, a configuration is known in which light emitted from a light source is reflected, by a light guide member having two reflection surfaces, toward: a position at which a toner image has been transferred and which is a position of a photosensitive drum on an upstream side in a traveling direction of the transfer target member; and a position at which a toner image has not been transferred and which is a position of a photosensitive drum on a downstream side in the traveling direction of the transfer target member. A configuration is also known in which grooves each having a triangular cross section are arranged in parallel over the entirety of an elongated light guide member having a cylindrical shape, along its longitudinal direction, and incident light is guided as the discharging light toward a photosensitive drum by the grooves.